Disclosure: I work for United Business Media, which produces the Enterprise 2.0 conference.

Since this is a group for Internal Community Managers, I don't think it's even a close contest between the two conferences you cited, Jackie. Look at the agenda for each. The Community conference program is packed with marketing-oriented external-facing community sessions. If you're running an internal community, I don't know of a better-targeted conference for you than Enterprise 2.0.

No big difference between the two events. 2009 was the first year for SF. Boston is the original, though I am not sure if that matters, as I believe SF had a very solid turnout, too.

Some overlap of speakers between the two events, but the conferences weren't clones by any means. We'd like you to attend both I'm closer to Boston so I'll likely continue to attend that one, personally.